Anvil for circular surgical stapler and associated method of manufacture with mim

ABSTRACT

A method is used to manufacture an anvil of a surgical circular stapler. The anvil includes a head and a shank extending proximally from the head. The method includes forming the head of a surgical circular stapler using a metal injection molding process. The method also includes forming an annular array of staple forming pockets in the head. The method also includes machining the shank of the surgical circular stapler. The method also includes coupling together the head and the shank of the surgical circular stapler that were separately manufactured.

BACKGROUND

In some surgical procedures (e.g., colorectal, bariatric, thoracic,etc.), portions of a patient's digestive tract (e.g., thegastrointestinal tract and/or esophagus, etc.) may be cut and removed toeliminate undesirable tissue or for other reasons. Once the tissue isremoved, the remaining portions of the digestive tract may be coupledtogether in an end-to-end anastomosis, an end-to-side anastomosis, or aside-to-side anastomosis. The anastomosis may provide a substantiallyunobstructed flow path from one portion of the digestive tract to theother portion of the digestive tract, without also providing any kind ofleaking at the site of the anastomosis.

One example of an instrument that may be used to provide an anastomosisis a circular stapler. Some such staplers are operable to clamp down onlayers of tissue, cut through the clamped layers of tissue, and drivestaples through the clamped layers of tissue to substantially seal thelayers of tissue together near the severed ends of the tissue layers,thereby joining the two severed ends of the anatomical lumen together.The circular stapler may be configured to sever the tissue and seal thetissue substantially simultaneously. For instance, the circular staplermay sever excess tissue that is interior to an annular array of staplesat an anastomosis, to provide a substantially smooth transition betweenthe anatomical lumen sections that are joined at the anastomosis.Circular staplers may be used in open procedures or in endoscopicprocedures. In some instances, a portion of the circular stapler isinserted through a patient's naturally occurring orifice.

Examples of circular staplers are described in U.S. Pat. No. 5,205,459,entitled “Surgical Anastomosis Stapling Instrument,” issued Apr. 27,1993; U.S. Pat. No. 5,271,544, entitled “Surgical Anastomosis StaplingInstrument,” issued Dec. 21, 1993; U.S. Pat. No. 5,275,322, entitled“Surgical Anastomosis Stapling Instrument,” issued Jan. 4, 1994; U.S.Pat. No. 5,285,945, entitled “Surgical Anastomosis Stapling Instrument,”issued Feb. 15, 1994; U.S. Pat. No. 5,292,053, entitled “SurgicalAnastomosis Stapling Instrument,” issued Mar. 8, 1994; U.S. Pat. No.5,333,773, entitled “Surgical Anastomosis Stapling Instrument,” issuedAug. 2, 1994; U.S. Pat. No. 5,350,104, entitled “Surgical AnastomosisStapling Instrument,” issued Sep. 27, 1994; and U.S. Pat. No. 5,533,661,entitled “Surgical Anastomosis Stapling Instrument,” issued Jul. 9,1996; and U.S. Pat. No. 8,910,847, entitled “Low Cost Anvil Assembly fora Circular Stapler,” issued Dec. 16, 2014. The disclosure of each of theabove-cited U.S. patents is incorporated by reference herein.

Some circular staplers may include a motorized actuation mechanism.Examples of circular staplers with motorized actuation mechanisms aredescribed in U.S. Pub. No. 2015/0083772, entitled “Surgical Stapler withRotary Cam Drive and Return,” published Mar. 26, 2015, now abandoned;U.S. Pub. No. 2015/0083773, entitled “Surgical Stapling Instrument withDrive Assembly Having Toggle Features,” published Mar. 26, 2015, nowU.S. Pat. No. 9,936,949, issued Apr. 10, 2018; U.S. Pub. No.2015/0083774, entitled “Control Features for Motorized Surgical StaplingInstrument,” published Mar. 26, 2015, now U.S. Pat. No. 9,907,552,issued Mar. 6, 2018; and U.S. Pub. No. 2015/0083775, entitled “SurgicalStapler with Rotary Cam Drive,” published Mar. 26, 2015, now U.S. Pat.No. 9,713,469, issued Jul. 25, 2017. The disclosure of each of theabove-cited U.S. patent Publications is incorporated by referenceherein.

While various kinds of surgical stapling instruments and associatedcomponents have been made and used, it is believed that no one prior tothe inventor(s) has made or used the invention described in the appendedclaims.

BRIEF DESCRIPTION OF THE DRAWINGS

While the specification concludes with claims which particularly pointout and distinctly claim this technology, it is believed this technologywill be better understood from the following description of certainexamples taken in conjunction with the accompanying drawings, in whichlike reference numerals identify the same elements and in which:

FIG. 1 depicts a perspective view of an exemplary circular stapler;

FIG. 2 depicts a perspective view of the circular stapler of FIG. 1,with a battery pack removed from a handle assembly and an anvil removedfrom a stapling head assembly;

FIG. 3 depicts a perspective view of the anvil of the circular staplerof FIG. 1;

FIG. 4 depicts another perspective view of the anvil of FIG. 3;

FIG. 5 depicts an exploded side elevational view of the anvil of FIG. 3;

FIG. 6 depicts a perspective view of the stapling head assembly of thecircular stapler of FIG. 1;

FIG. 7 depicts a perspective sectional view of an inner body member ofthe stapling head assembly of FIG. 6;

FIG. 8 depicts a perspective view of a first exemplary alternative anvilthat may be incorporated into the circular stapler of FIG. 1;

FIG. 9 depicts an exploded perspective view of the anvil of FIG. 8,where the anvil includes a shank, a head, and a cap;

FIG. 10 depicts an exploded perspective view of the shank and the headof the anvil of FIG. 8, where the head includes an annular array ofstaple forming pockets;

FIG. 11 depicts a perspective view of the head of FIG. 10, but where theannular array of staple forming pockets are not yet formed;

FIG. 12 depicts another perspective view of the head of FIG. 11;

FIG. 13A depicts a staple forming pocket prior to being coined orelectrochemically machined;

FIG. 13B depicts the staple forming pocket of FIG. 13A, but after beingcoined or electrochemically machined;

FIG. 14A depicts a central portion of the staple forming pocket of FIG.13A, taken along line 14A-14A of FIG. 13A;

FIG. 14B depicts a central portion of the staple forming pocket of FIG.13B, taken along line 14B-14B of FIG. 13B;

FIG. 15A depicts a portion of the staple forming pocket of FIG. 13A,taken along line 15A-15A of FIG. 13A;

FIG. 15B depicts a portion of the staple forming pocket of FIG. 13B,taken along line 15B-15B of FIG. 13B;

FIG. 16 depicts an annular array of individual staple forming pockets ofFIG. 13B after being coined or electrochemically machined;

FIG. 17 depicts another annular array of individual staple formingpockets after being coined or electrochemically machined;

FIG. 18 depicts a perspective exploded view of a second exemplaryalternative anvil that may be incorporated into the circular stapler ofFIG. 1;

FIG. 19 depicts a perspective exploded view of a third exemplaryalternative anvil that may be incorporated into the circular stapler ofFIG. 1; and

FIG. 20 depicts an exemplary method of manufacturing the anvil of FIG. 8that may be incorporated into the circular stapler of FIG. 1.

The drawings are not intended to be limiting in any way, and it iscontemplated that various embodiments of the technology may be carriedout in a variety of other ways, including those not necessarily depictedin the drawings. The accompanying drawings incorporated in and forming apart of the specification illustrate several aspects of the presenttechnology, and together with the description serve to explain theprinciples of the technology; it being understood, however, that thistechnology is not limited to the precise arrangements shown.

DETAILED DESCRIPTION

The following description of certain examples of the technology shouldnot be used to limit its scope. Other examples, features, aspects,embodiments, and advantages of the technology will become apparent tothose skilled in the art from the following description, which is by wayof illustration, one of the best modes contemplated for carrying out thetechnology. As will be realized, the technology described herein iscapable of other different and obvious aspects, all without departingfrom the technology. Accordingly, the drawings and descriptions shouldbe regarded as illustrative in nature and not restrictive.

It is further understood that any one or more of the teachings,expressions, embodiments, examples, etc. described herein may becombined with any one or more of the other teachings, expressions,embodiments, examples, etc. that are described herein. Thefollowing-described teachings, expressions, embodiments, examples, etc.should therefore not be viewed in isolation relative to each other.Various suitable ways in which the teachings herein may be combined willbe readily apparent to those of ordinary skill in the art in view of theteachings herein. Such modifications and variations are intended to beincluded within the scope of the claims.

For clarity of disclosure, the terms “proximal” and “distal” are definedherein relative to a human or robotic operator of the surgicalinstrument. The term “proximal” refers the position of an element closerto the human or robotic operator of the surgical instrument and furtheraway from the surgical end effector of the surgical instrument. The term“distal” refers to the position of an element closer to the surgical endeffector of the surgical instrument and further away from the human orrobotic operator of the surgical instrument. In addition, the terms“first” and “second” are used herein to distinguish one or more portionsof the surgical instrument. For example, a first assembly and a secondassembly may be alternatively and respectively described as a secondassembly and a first assembly. The terms “first” and “second” and othernumerical designations are merely exemplary of such terminology and arenot intended to unnecessarily limit the invention described herein.

I. Overview of Exemplary Circular Stapling Surgical Instrument

A. Exemplary Circular Stapling Surgical Instrument

FIGS. 1-2 depict an exemplary surgical circular stapling instrument (10)that may be used to provide an end-to-end, side-to-side, or end-to-sideanastomosis between two sections of an anatomical lumen such as aportion of a patient's digestive tract. Instrument (10) of this examplecomprises a handle assembly (100), a shaft assembly (200), a staplinghead assembly (300), and an anvil (400). Handle assembly (100) comprisesa casing (110) defining an obliquely oriented pistol grip (112). In someversions, pistol grip (112) is perpendicularly oriented. In some otherversions, pistol grip (112) is omitted. Handle assembly (100) furtherincludes a user feedback feature (114) that permits viewing of a movableindicator needle (not shown) as will be described in greater detailbelow. In some versions, a series of hash marks, colored regions, and/orother fixed indicators are positioned adjacent to user feedback feature(114) in order to provide a visual context for indicator needle.

Instrument (10) includes a battery pack (120). Battery pack (120) isoperable to provide electrical power to a motor (160) in pistol grip(112). In particular, as shown in FIGS. 1-2, battery pack (120) may beinserted into a socket (116) defined by casing (110). Once battery pack(120) is fully inserted in socket (116), latches (122) of battery pack(120) may resiliently engage interior features of casing (110) toprovide a snap fit. It should be understood that battery pack (120) andhandle assembly (100) may have complementary electrical contacts, pinsand sockets, and/or other features that provide paths for electricalcommunication from battery pack (120) to electrically powered componentsin handle assembly (100) when battery pack (120) is inserted in socket(116). Shaft assembly (200) extends distally from handle assembly (100)and includes a preformed bend. In some versions, the preformed bend isconfigured to facilitate positioning of stapling head assembly (300)within a patient's colon. Various suitable bend angles or radii that maybe used will be apparent to those of ordinary skill in the art in viewof the teachings herein.

Stapling head assembly (300) is located at the distal end of shaftassembly (200). As shown in FIGS. 1-2, anvil (400) is configured toremovably couple with shaft assembly (200), adjacent to stapling headassembly (300). Anvil (400) and stapling head assembly (300) areconfigured to cooperate to manipulate tissue in three ways, includingclamping the tissue, cutting the tissue, and stapling the tissue. A knob(130) at the proximal end of handle assembly (100) is rotatable relativeto casing (110) to provide precise clamping of the tissue between anvil(400) and stapling head assembly (300). When a safety trigger (140) ofhandle assembly (100) is pivoted away from a firing trigger (150) ofhandle assembly (100), firing trigger (150) may be actuated to therebyprovide cutting and stapling of the tissue.

A. Exemplary Anvil

As shown in FIGS. 3-5, anvil (400) includes a head (410) and a shank(420). Head (410) includes a proximal surface (412) that defines anannular array of staple forming pockets (414). Staple forming pockets(414) are arranged in two concentric annular arrays in the presentexample. In some other versions, staple forming pockets (414) arearranged in three or more concentric annular arrays. Staple formingpockets (414) are configured to deform staples as the staples are driveninto staple forming pockets (414). For instance, each staple formingpocket (414) may deform a generally “U” shaped staple into a “B” shapeas is known in the art. As best seen in FIG. 4, proximal surface (412)terminates at an inner edge (416), which defines an outer boundary of anannular recess (418) surrounding shank (420).

Shank (420) defines a bore (422) and includes a pair of pivoting latchmembers (430) positioned in bore (422). As best seen in FIG. 5, eachlatch member (430) includes a “T” shaped distal end (432), a roundedproximal end (434), and a latch shelf (436) located distal to proximalend (434). “T” shaped distal ends (432) secure latch members (430)within bore (422). Latch members (430) are positioned within bore (422)such that distal ends (434) are positioned at the proximal ends oflateral openings (424), which are formed through the sidewall of shank(420). Lateral openings (424) thus provide clearance for distal ends(434) and latch shelves (436) to deflect radially outwardly from thelongitudinal axis defined by shank (420). However, latch members (430)are configured to resiliently bias distal ends (434) and latch shelves(436) to pivot radially inwardly toward the longitudinal axis defined byshank (420). Latch members (430) thus act as retaining clips. Thisallows anvil (400) to be removably secured to a trocar (330) of staplinghead assembly (300) as will be described in greater detail below. Whenshank (420) is secured to trocar (330) and trocar (330) is retractedproximally, the inner diameter of bore (314) in inner core member (312)of body member (310) laterally constrains latch members (430) tomaintain engagement between latch shelves (436) and proximal surface(338) of head (334) of trocar (330). This engagement prevents anvil(400) from being released from trocar (330) during firing of staplinghead assembly (300). It should be understood, however, that latchmembers (436) are merely optional. Anvil (400) may be removably securedto a trocar (330) using any other suitable components, features, ortechniques. As shown in FIG. 4, anvil (400) of the present exampleincludes a breakable washer (417) within annular recess (418). Thiswasher (417) is broken by knife member (340) when the knife member (340)completes a full distal range of motion.

As shown in FIGS. 3-4, shank (420) of the present example includes a setof longitudinally extending splines (426) that are spaced about shank(420) in an angular array. The proximal end of each spline (426)includes a respective lead-in edge (428). As described in greater detailbelow, splines (426) are configured to engage corresponding splines(316) of an inner body member (310) of stapling head assembly (300) inorder to consistently provide a predetermined angular alignment betweenanvil (400) and stapling head assembly (300). As also described below,this angular alignment may ensure that staple forming pockets (414) ofanvil (400) are consistently angularly aligned appropriately with stapleopenings (324) of stapling head assembly (300). Thus, in the presentexample, splines (426) are precisely and consistently positioned inrelation to staple forming pockets (414). In versions where head (410)and shank (420) are initially formed as separate pieces and then laterjoined together, the machine or other device that is used to join head(410) and shank (420) together may have appropriate indexingcapabilities in order to reliably and consistently achieve the properangular positioning of head (410) and shank (420) to thereby provideprecise and consistent positioning of splines (426) in relation tostaple forming pockets (414). Various suitable ways in which suchresults may be achieved will be apparent to those of ordinary skill inthe art in view of the teachings herein. In some other versions, head(410) and shank (420) are formed together simultaneously, as a singleunitary construction.

C. Exemplary Stapling Head Assembly

As best seen in FIGS. 7-8, stapling head assembly (300) of the presentexample is coupled to a distal end of shaft assembly (200) and comprisesa body member (310) and a slidable staple driver member (not shown).Body member (310) includes a distally extending cylindraceous inner coremember (312). Body member (310) is fixedly secured to an outer sheath(210) of shaft assembly (200). Body member (310) and outer sheath (210)thus serve together as a mechanical ground for stapling head assembly(300).

As shown in FIG. 7, inner core member (312) of body member (310) definesa bore (314). A plurality of longitudinally extending splines (316) areequidistantly spaced in an angular array within bore (314). The distalends of splines (316) include lead-in edges (318) that are configured tocomplement lead-in edges (428) of splines (426) on shank (420) of anvil(400). In particular, after shank (420) is secured to trocar (330) asdescribed in greater detail below, and as anvil (420) is thereafterretracted proximally relative to stapling head assembly (300) as alsodescribed in greater detail below, lead-in edges (318, 428) maycooperatively engage each other to drive anvil (400) to rotate relativeto trocar (330) to angularly align splines (426) of anvil (400) with thegaps between splines (316) of body member (310). The gaps betweensplines (316) may be configured to have a width that is substantiallyequal to the width of splines (426). In this manner, when splines (426)of anvil (400) are positioned within the gaps between splines (316) ofbody member (310), anvil (400) may achieve a predetermined angularalignment relative to stapling head assembly (300). This predeterminedangular alignment may ensure that staple openings (324) of deck member(320) are precisely aligned with corresponding staple forming pockets(414) of anvil (400). Thus, splines (316, 426) are configured tocooperate with each other to ensure that staples ejected through stapleopenings (324) are accurately driven into corresponding staple formingpockets (414, 510, 530) on a consistent basis, regardless of the angularorientation of anvil (400) relative to stapling head assembly (300) atthe time anvil (400) is initially secured to trocar (330).

Trocar (330) is positioned coaxially within inner core member (312) ofbody member (310). Trocar (330) includes a colored region (333). As willbe described in greater detail below, trocar (330) is operable totranslate distally and proximally relative to body member (310) inresponse to rotation of knob (130) relative to casing (110) of handleassembly (100). Trocar (330) comprises a shaft (332) and a head (334).Head (334) includes a pointed tip (336) and an inwardly extendingproximal surface (338). Shaft (332) thus provides a reduced outerdiameter just proximal to head (334), with surface (338) providing atransition between that reduced outer diameter of shaft (332) and theouter diameter of head (334). While tip (336) is pointed in the presentexample, tip (336) is not sharp. Tip (336) will thus not easily causetrauma to tissue due to inadvertent contact with tissue. Head (334) andthe distal portion of shaft (332) are configured for insertion in bore(422) of anvil (420). Proximal surface (338) and latch shelves (436)have complementary positions and configurations such that latch shelves(436) engage proximal surface (338) when shank (420) of anvil (400) isfully seated on trocar (330). Anvil (400) is thus secured to trocar(330) through a snap fit due to latch members (430). Knife member (340)includes a distally presented, sharp circular cutting edge (342). Knifemember (340) also defines an opening that is configured to coaxiallyreceive core member (312) of body member (310).

A deck member (320) is fixedly secured to body member (310). Deck member(320) includes a distally presented deck surface (322) defining twoconcentric annular arrays of staple openings (324). Staple openings(324) are arranged to correspond with the arrangement of staple driversand staple forming pockets (414) described above. Thus, each stapleopening (324) is configured to provide a path for a corresponding stapledriver to drive a corresponding staple through deck member (320) andinto a corresponding staple forming pocket (414) when stapling headassembly (300) is actuated. It should be understood that the arrangementof staple openings (322) may be modified just like the arrangement ofstaple forming pockets (414) as described above. It should also beunderstood that various structures and techniques may be used to containstaples within stapling head assembly (300) before stapling headassembly (300) is actuated. Such structures and techniques that are usedto contain staples within stapling head assembly (300) may prevent thestaples from inadvertently falling out through staple openings (324)before stapling head assembly (300) is actuated. Various suitable formsthat such structures and techniques may take will be apparent to thoseof ordinary skill in the art in view of the teachings herein. As bestseen in FIG. 7, deck member (320) defines an inner diameter that is justslightly larger than the outer diameter defined by knife member (340).Deck member (320) is thus configured to allow knife member (340) totranslate distally to a point where cutting edge (342) is distal to decksurface (322).

II. Exemplary Anvils and Methods of Manufacture

As described above, anvil (400) of instrument (10) may be machined as asingle unitary component or anvil (400) may be manufactured by initiallyforming head (410) and shank (420) as separate pieces and then laterjoining head (410) and shank (420) together. Because head (410) andshank (420) may be initially formed as separate pieces, it may bedesirable to strengthen the coupling between head (410) and shank (420).Additionally, it may be desirable to make head (410) and shank (420)using different manufacturing processes and in a low-cost manner.Moreover, it may be desirable to refine certain portions and surfaces ofhead (410) and/or shank (420) to improve the operability anvil (400)with instrument (10). Therefore, it may therefore be desirable tomanufacture exemplary anvils (500, 600, 700) that address these andother shortcomings, while also enabling anvils (500, 600, 700) tofunction interchangeably with anvil (400) described above with referenceto FIGS. 1-5.

As will be described with reference to FIGS. 9-20, surgical instrument(10) includes anvil (500, 600, 700), that is intended to be used inplace of anvil (400) described above with reference to FIGS. 1-5. Aspreviously described, surgical instrument (10) includes a body (shown ashandle assembly (100)), shaft assembly (200) extending distally fromhandle assembly (100), stapling head assembly (300), and anvil (400).Stapling head assembly (300) is positioned at a distal end of shaftassembly (200). Stapling head assembly (300) includes an anvil couplingfeature (shown as trocar (330)), at least one annular array of staples,and the staple driver. As will be described in greater detail below andsimilar to the functionality of anvil (400), anvils (500, 600, 700) areeach configured to couple with trocar (330) and each are configured todeform staples driven by the staple driver.

A. First Exemplary Alternative Anvil

FIGS. 9-12 show various perspective views of a first exemplary anvil(500) that may be incorporated into instrument (10) of FIG. 1. Anvil(500) includes a head (510) and a shank (520). Shank (520) extendsproximally from head (510) and is configured to be coupled with head(510) once formed. Head (510) includes a proximal surface (512) thatdefines an annular array of staple forming pockets (514) shown in FIG.10. As shown, staple forming pockets (514) are arranged in twoconcentric annular arrays, similar to those shown in FIG. 16.Alternatively, staple forming pockets (514 b) may be arranged in threeor more concentric annular arrays, similar to those shown in FIG. 17.

Staple forming pockets (514) are configured to deform the staples as thestaples are driven into staple forming pockets (514). For instance, eachstaple forming pocket (514) may deform a generally “U” shaped stapleinto a “B” shape as is known in the art. As shown in FIGS. 10 and 11,proximal surface (512) of head (510) terminates at an inner edge (516),which defines an outer boundary of an annular recess (518) surroundingshank (520). As will be described in greater detail with reference toFIG. 10, head (510), including staple forming pockets (514), may beformed using an injection molding process, such as a metal injectionmolding process. Metal injection molding (MIM) refers to anymetalworking process where finely-powdered metal is mixed with a bindermaterial to create a feedstock that is subsequently shaped andsolidified using molding process (such as injection molding). Metalinjection molding allows for high volume, complex parts to be shaped.Alternatively, head (510) may be formed from a polymeric material usingan injection molding process. As will be described in greater detailwith reference to FIGS. 13A-16, at least a portion of at least onestaple forming pocket (514) may be coined or electrochemically machinedto improve one or more properties of staple forming pockets (514).

Shank (520) includes a longitudinally extending body (521) that definesa bore (522) and may include a pair of pivoting latch members (notshown) positioned in bore (522), that may be similar in structure andfunction to latch members (430) described above with reference to shank(420) of anvil (400). The latch members are positioned within bore (522)such that the distal ends are positioned at the proximal ends of lateralopenings (524), which are formed through the sidewall of shank (520).Lateral openings (524) provide clearance for the latch member to deflectradially outwardly from the longitudinal axis defined by shank (520).The latch members allow anvil (500) to be removably secured to a trocar(330) of stapling head assembly (300). When shank (520) is secured totrocar (330) and trocar (330) is retracted proximally, the innerdiameter of bore (314) in inner core member (312) of body member (310)laterally constrains the latch members to maintain engagement withproximal surface (338) of head (334) of trocar (330). This engagementprevents anvil (500) from being released from trocar (330) during firingof stapling head assembly (300). The latch members may be omitted, suchthat anvil (500) may be removably secured to a trocar (330) using anyother suitable components, features, or techniques.

As shown in FIGS. 8-10, shank (520) includes a set of longitudinallyextending splines (526) that are spaced about shank (520) in an angulararray. The proximal end of each spline (526) includes a respectivelead-in edge (528). Splines (526) are configured to engage correspondingsplines (316) of an inner body member (310) of stapling head assembly(300) to consistently provide a predetermined angular alignment betweenanvil (500) and stapling head assembly (300). This angular alignment mayensure that staple forming pockets (514) of anvil (500) are consistentlyangularly aligned appropriately with staple openings (324) of staplinghead assembly (300). Thus, splines (526) are precisely and consistentlypositioned in relation to staple forming pockets (514). As shown in FIG.9, shank (520) further includes a flange (540) extending radiallyoutward from a distal end (542) of shank (520). As a result, flange(540) has a larger area than longitudinally extending body (521) ofshank (520). Flange (540) includes opposing proximal and distal surfaces(544, 546). As described in greater detail with reference to FIG. 20,shank (520) may be machined using one or more machining processes.

As shown in FIGS. 9 and 12, head (510) includes a recessed portion (548)that extends proximally from a distal outer surface (550). Recessedportion (548) includes a recessed surface (552) surrounded by an annularwall (554), with an aperture (556) extending through recessed surface(552) that is configured to receive longitudinally extending body (521)of shank (520). As shown, aperture (556) is concentric to both distalouter surface (550) and recessed surface (552); however, otherpositionings of aperture (556) relative to distal outer surface (550)and recessed surface (552) are also envisioned. As shown in FIGS. 8-10,recessed portion (548) is sized and configured to receive flange (540)of shank (520). While recessed portion (548) and flange (540) are shownas circular, it is also envisioned that recessed portion (548) andflange (540) may have a variety of other shapes (e.g. rectangular) thatmay prevent relative rotation of head (510) and shank (520), if desired.

Distal outer surface (555) also includes one or more recesses (558),with two being shown, which may be used to secure a distal feature (suchas a cap). Head (510) may also include a tapered portion (560) extendingproximally from distal outer surface (550). Tapered portion (560) isshown as a chamfer. Recessed surface (552) of recessed portion (548) maybe in direct contact with proximal surface (544) of flange (520) oncehead (510) is coupled with shank (520). As shown in FIG. 8, distal outersurface (550) of head (510) is generally flush with distal surface offlange (540) after head (510) is coupled with shank (520). In otherwords, the depth of recessed portion (548) is about the same as thethickness of flange (540). However, the depth of recessed portion (548)and/or the thickness of flange (540) may vary. Additionally, distalouter surface (550) may be arcuate, if desired.

As shown in FIG. 9, head (510) may be coupled to shank (520) using a cap(562), shown as a thin anvil plate. Cap (562) is configured to sandwichflange (540) of shank (520) between cap (562) and head (510). Cap (562)includes proximal and distal surfaces (564, 566). According to anembodiment, cap (562) may be a material (e.g. polymeric material)overmolded onto head (510) using one or more overmolding processes. Morespecifically, cap (562) may be overmolded onto distal surface (546) offlange (540) and/or distal outer surface (550) of head (510). As aresult, cap (562) may not be a separate component. Alternatively, cap(562) may be selectively coupleable to head (510) using one or moresecurement features that are configured to couple with recess (558). Asshown, cap (562) is formed from a polymeric material; however, cap (562)may be formed from any suitable material.

Staple forming pockets (514) may be formed simultaneously with or afterhead (510) is formed. For example, FIGS. 11 and 12 show perspectiveviews of head (510), but with staple forming pockets (514) not yetformed. As described in greater detail with reference to FIG. 20, atleast a portion of head (510) may be machined after forming head (510)if desired.

As shown in FIGS. 13A-16, at least a portion of staple forming pocket(514) may be coined or electrochemical machined after forming stapleforming pocket (514) using an injection molding process (e.g. a metalinjection molding process). More specifically, FIG. 13A shows a stapleforming pocket (514 a) prior to being coined or electrochemicallymachined, while FIG. 13B shows the staple forming pocket (514) of FIG.13A, after being coined or electrochemically machined. As shown in FIG.13A, staple forming pocket (514 a) includes a central portion (570 a)disposed between outer portions (572 a, 574 a). As shown in FIGS. 13B,14B, and 15B, central portion (570) of staple forming pocket (514) issubsequently coined or electrochemically machined, which results in asmoother surface and a denser surface than another portion (e.g. outerportions (572, 574)) that was not coined or electrochemical machined. Asa result, outer portions (572, 574) have surface that is rougher andless dense than central portion (570) of staple forming pocket (514).Alternatively, the entire staple forming pocket (514), including outerportions (572, 574), may be coined or electrochemically machined, ifdesired.

Coining is a form of precision stamping where a workpiece is subjectedto a sufficiently high stress to induce plastic flow on the surface ofthe material. The plastic flow reduces surface grain size and workhardens the surface of the workpiece, while the material deeper withinthe workpiece retains its toughness and ductility. Coining also improvesthe dimensional tolerances of staple forming pocket (514).Electrochemical machining (ECM) is a method of removing metal using oneor more electrochemical processes. Electrochemical machining may be usedfor mass production due to cost effectiveness and is utilized forworking extremely hard materials or materials that are difficult tomachine using conventional methods. Electrochemical machining may cutsmall or uniquely-shaped angles, intricate contours, or cavities in hardmetals workpieces.

FIG. 14A shows central portion (570 a) of staple forming pocket (514 a)taken along line 14A-14A of FIG. 13A, while FIG. 14B shows centralportion (570) of staple forming pocket (514), taken along line 14B-14Bof FIG. 13B. As shown when comparing FIG. 14A with FIG. 14B, centralportion (570 a) having been coined or electrochemically machined is bothsmoother and denser than another portion (e.g. outer portions (572,574)) of the same staple forming pocket (514) that was not coined orelectrochemically machined.

FIG. 15A shows a portion of staple forming pocket (514 a) of FIG. 13A,taken along line 15A-15A, while FIG. 15B shows a portion of stapleforming pocket (514) of FIG. 13B, taken along line 15B-15B. As shownwhen comparing FIG. 15A with FIG. 15B, a channel (576) results after thecoining or electrochemical machining process. FIG. 16 shows an annulararray of staple forming pockets (514) of FIG. 13B, after being coined orelectrochemically machined. More specifically, central portions (570)are coined or electrochemically machined.

FIG. 17 shows another an annular array of staple forming pockets (514 b)after being coined or electrochemically machined. Similar to stapleforming pockets (514), staple forming pockets (514 b) also include acentral portion (570 b) and outer portions (572 b, 574 b). As shown, acentral portion (570 b) is coined or electrochemically machined, and asa result, is both smoother and denser than another portion (e.g. outerportions (572 b, 574 b)) of same staple forming pocket (514 b) that isnot coined or electrochemically machined.

B. Second Exemplary Alternative Anvil

FIG. 18 shows a perspective view of a second exemplary anvil (600) thatmay be incorporated into instrument (10) of FIG. 1 in place of anvil(400, 500) described above. Similar to anvil (500), anvil (600) includesa head (610), a shank (620), and a cap (662). As discussed in greaterdetail below, unlike cap (562), cap (662) includes one or moreengagement features. Similar to head (510), head (610) includes aproximal surface (612), staple forming pockets (614), a recessed portion(648), a distal outer surface (650), a recessed surface (652), anannular wall (654), an aperture (656), recesses (658), and a taperedportion (660). Similar to shank (520), shank (620) includes a bore(622), lateral openings (624), a set of longitudinally extending splines(626), lead-in edges (628), a flange (640), and a distal end (642).Similar to flange (540), flange (640) includes opposing proximal anddistal surfaces (644, 646). Similar to cap (562), cap (662) includesopposing proximal distal surfaces (664, 666).

Proximal surface (612) of head (610) defines an annular array of stapleforming pockets (614), which are similar to those shown in FIG. 10. Asdescribed in greater detail with reference to FIG. 20, head (610),including staple forming pockets (614), may be formed using a metalinjection molding process and subsequently machined using one or moremachining processes. As previously described with reference to stapleforming pocket (514) in FIGS. 13A-16, at least a portion of at least onestaple forming pocket (614) may be coined or electrochemically machinedto improve one or more properties of staple forming pockets (614).Recessed portion (648) of head (610) extends proximally from distalouter surface (650). Recessed surface (652) is surrounded by annularwall (654), with aperture (656) extending through recessed surface(652). Aperture (656) is configured to receive longitudinally extendingbody (621) of shank (620) therethrough. Recessed portion (648) is sizedand configured to receive flange (640) of shank (620). Recessed portion(648) of head (610) may be in direct contact with proximal surface (644)of flange (620), once head (610) is coupled with shank (620). Distalouter surface (655) of head (610) also includes one or more recesses(658), with two being shown, which may be used to secure a distalfeature, such as cap (662). Tapered portion (660) extends proximallyfrom distal outer surface (650).

As shown in FIG. 18, shank (620) extends proximally from head (610) andis configured to be coupled with head (610) once formed. While not shownin FIGS. 8-12, shank (620) includes an outwardly extending portion(630). As shown in FIG. 18, flange (640) extending radially outward fromdistal end (642) of shank (620). Flange (640) includes opposing proximaland distal surfaces (644, 646). As described in greater detail withreference to FIG. 20, shank (620) may be formed using a metal injectionmolding process and subsequently machined using one or more machiningprocesses. As a result, both head (610) and shank (620) may beseparately formed using metal injection molding processes. Additionally,both head (610) and shank (620) may be separately machined after beingformed from the respective metal injection molding processes.

Head (610) may be coupled to shank (620) using cap (662), shown in thisexemplary embodiment as an arcuate cap. Cap (662) is configured tosandwich flange (640) of shank (620) between cap (662) and head (610).Unlike cap (562), cap (662) is selectively couplable to head (610) usingone or more securement features. For example, cap (662) may include atleast one proximally facing projection (668), that is configured tocouple with at least one corresponding recess (658). As such, couplingcap (662) with head (610) includes inserting proximally facingprojections (668) into recesses (658). While each recess (662) is shownas extending completely through distal outer surface (650), it isenvisioned that recesses (658) may extend only partly through distalouter surface (650). While cap (662) is shown as being formed from apolymeric material; it is envisioned that cap (662) may be formed fromany suitable material. As shown, distal surface (666) of cap (662) isrounded, forming a hemispherical shape.

C. Third Exemplary Alternative Anvil

FIG. 19 shows a perspective view of a third exemplary anvil (700) thatmay be incorporated into instrument (10) of FIG. 1 in place of anvil(400, 500) described above. Similar to anvil (500), anvil (700) includesa head (710) and a shank (720). Similar to head (510), head (710)includes a proximal surface (712), staple forming pockets (714), arecessed portion (748), a distal outer surface (750), a recessed surface(752), an annular wall (754), an aperture (756), and a tapered portion(760). Similar to shank (520), shank (720) includes a bore (722),lateral openings (724), a set of longitudinally extending splines (726),lead-in edges (728), and a flange (740) and a distal end (742). Similarto flange (540), flange (740) includes opposing proximal and distalsurfaces (744, 746).

Proximal surface (712) of head (710) defines an annular array of stapleforming pockets (714), which are similar to those shown in FIG. 10. Asdescribed in greater detail with reference to FIG. 20, head (710),including staple forming pockets (714), may be formed using a metalinjection molding process and subsequently machined using one or moremachining processes. As previously described with reference to stapleforming pocket (514) in FIGS. 13A-16, at least a portion of at least onestaple forming pocket (714) may be coined or electrochemically machinedto improve one or more properties of staple forming pockets (714).Recessed portion (748) of head (710) extends proximally from distalouter surface (750). Recessed surface (752) is surrounded by annularwall (754), with aperture (756) extending through recessed surface(752). Aperture (756) is configured to receive longitudinally extendingbody (721) of shank (720) therethrough. Recessed portion (748) is sizedand configured to receive flange (740) of shank (720). Recessed surface(752) of recessed portion (748) may be in direct contact with proximalsurface (744) of flange (720), once head (710) is coupled with shank(720). Tapered portion (760) extends proximally from distal outersurface (750).

As shown in FIG. 19, shank (720) extends proximally from head (710) andis configured to be coupled with head (710) once formed. While not shownin FIGS. 8-12, shank (720) includes an outwardly extending portion(730). As shown in FIG. 19, flange (740) extend radially outward fromdistal end (742) of shank (720). Flange (740) includes opposing proximaland distal surfaces (744, 746). Distal surface (746) of flange (740)includes an inner shallow portion (762) and a rounded outer edge portion(764). As shown, rounded outer edge portion (764) includes a distal mostportion (766) that is the distal most point of shank (720). A proximalsurface (744) of flange (740) is coupled with distal outer surface (750)of head (710). Shank (720) may be formed using a metal injection moldingprocess and subsequently machined using one or more machining processes.

D. Exemplary Method of Manufacture

FIG. 20 shows an exemplary method (800) of manufacturing anvils (500,600, 700) that may be incorporated into instrument (10) of FIG. 1. Aspreviously described, anvil (500, 600, 700) includes head (510, 610,710) and shank (520, 620, 720) that extends proximally from head (510,610, 710). At step (802), method (800) includes forming head (510, 610,710), including staple forming pockets (514, 614, 714), using aninjection molding machine (812). Staple forming pockets (514, 614, 714)may be formed simultaneously with or after head (510, 610, 710) isformed using a metal injection molding. For example, head (510, 610,710) may be formed using a metal injection molding process using a metalinjection molding machine. At step (804), method (800) includesmachining at least a portion of head (510, 610, 710). Machining mayinclude coining or electrochemical machining at least a portion of atleast one staple forming pocket (514, 614, 714) using a stamping or ECMmachine (814). As previously described, the portion of staple formingpocket (514, 614, 714) coined or electrochemically machined is bothsmoother and denser than another portion that was not coined orelectrochemical machined. Other benefits may also be achieved.

At step (806), method (800) includes forming shank (520, 620, 720) usingan injection molding machine (816). Injection molding machine (816) maybe the same or different than injection molding machine (812). Shank(520, 620, 720) may be formed using a metal injection molding processusing a metal injection molding machine. At step (808), method (800)includes machining shank (520, 620, 720) using a lathe (818). Ifdesired, shank (520, 620, 720) may be machined from a single piece ofmaterial without be previously formed using an injection moldingprocess.

At step (810), method (800) includes coupling head (510, 610, 710) withshank (520, 620, 720) that were separately manufactured. Coupling head(510, 610) with shank (520, 620) may include coupling cap (562, 662)with head (510, 610) to sandwich flange (540, 640) of shank (520, 620)between cap (562, 662) and head (510, 610). More specifically, where cap(662) includes proximally facing projections (668), coupling cap (662)with head (610) includes inserting proximally facing projections (668)into recesses (658) of head (610). It is envisioned that coupling head(510, 610, 710) with shank (520, 620, 720) may include, for example, oneor more overmolding, welds, adhesive, and/or mechanical securementfeatures (e.g. projections (668)).

Those of ordinary skill in the art will understand that staples formedby anvil (400, 500, 600, 700) will have a three-dimensional profile,where the legs are angularly offset from a plane passing through a crownof the staple; in addition to being bent generally toward each other. Byway of example only, the staples formed using anvil (400, 500, 600, 700)may have an appearance similar to at least some of the staples shown anddescribed in U.S. Pub. No. 2014/0239037, entitled “Staple FormingFeatures for Surgical Stapling Instrument,” published Aug. 28, 2014, nowU.S. Pat. No. 10,092,292, issued on Oct. 9, 2018, the disclosure ofwhich is incorporated by reference herein. By way of further exampleonly, the staples formed using anvil (400, 500, 600, 700) may have anappearance similar to at least some of the staples shown and describedin U.S. Pat. Pub. No. 2018/0132849, entitled “Staple Forming PocketConfigurations for Circular Surgical Stapler Anvil,” published May 17,2018, the disclosure of which is incorporated by reference herein.Additional features of anvils are disclosed in U.S. Pub. No.2017/0258471 published Sep. 14, 2017; U.S. Pub. No. 2015/0083772published Mar. 26, 2015, now abandoned; U.S. Pub. No. 2015/0083774published Mar. 26, 2015, now U.S. Pat. No. 9,907,552, issued Mar. 6,2018; U.S. Pub. No. 2016/0374672 published Dec. 29, 2016; U.S. Pub. No.2018/0132853 published May 17, 2018; U.S. Pub. No. 2018/0132849published May 17, 2018, U.S. patent application Ser. No. 15/581,640,entitled “Liquid-Immune Trigger Circuit for Surgical Instrument,” filedApr. 28, 2017, and U.S. patent application Ser. No. 15/581,546, entitled“Hysteresis Removal Feature in Surgical Stapling Instrument,” filed Apr.28, 2017, the disclosures of which are incorporated by reference herein.

In addition to or in lieu of the foregoing, anvil (400, 500, 600, 700)may be further constructed and operable in accordance with at least someof the teachings of U.S. Pat. Nos. 5,205,459; 5,271,544; 5,275,322;5,285,945; 5,292,053; 5,333,773; 5,350,104; 5,533,661; and/or U.S. Pat.No. 8,910,847, the disclosures of which are incorporated by referenceherein. Still other suitable configurations will be apparent to one ofordinary skill in the art in view of the teachings herein.

III. Exemplary Combinations

The following examples relate to various non-exhaustive ways in whichthe teachings herein may be combined or applied. The following examplesare not intended to restrict the coverage of any claims that may bepresented at any time in this application or in subsequent filings ofthis application. No disclaimer is intended. The following examples arebeing provided for nothing more than merely illustrative purposes. It iscontemplated that the various teachings herein may be arranged andapplied in numerous other ways. It is also contemplated that somevariations may omit certain features referred to in the below examples.Therefore, none of the aspects or features referred to below should bedeemed critical unless otherwise explicitly indicated as such at a laterdate by the inventors or by a successor in interest to the inventors. Ifany claims are presented in this application or in subsequent filingsrelated to this application that include additional features beyondthose referred to below, those additional features shall not be presumedto have been added for any reason relating to patentability.

EXAMPLE 1

A method of manufacturing an anvil of a surgical circular stapler,wherein the anvil includes a head and a shank extending proximally fromthe head, the method comprising: (a) forming the head of a surgicalcircular stapler using a metal injection molding process; (b) forming anannular array of staple forming pockets in the head; (c) machining theshank of the surgical circular stapler; and (d) coupling together thehead and the shank of the surgical circular stapler that were separatelymanufactured.

EXAMPLE 2

The method of Example 1, further comprising: forming the shank using ametal injection molding process prior to machining the shank.

EXAMPLE 3

The method of any one or more of Examples 1 through 2, furthercomprising: machining at least a portion of the head after forming thehead using the metal injection molding process.

EXAMPLE 4

The method of any one or more of Examples 1 through 2, wherein formingthe head using the metal injection molding process and forming theannular array of staple forming pockets in the head are performedsimultaneously.

EXAMPLE 5

The method of any one or more of Examples 1 through 2, wherein formingthe head using the metal injection molding process occurs before formingthe annular array of staple forming pockets in the head.

EXAMPLE 6

The method of any one or more of Examples 1 through 5, wherein afterforming the annular array of staple forming pockets using the metalinjection molding process, the method further comprises coining orelectrochemical machining at least a portion of at least one stapleforming pocket of the annular array of staple forming pockets.

EXAMPLE 7

The method of Example 6, wherein the portion coined or electrochemicallymachined is both smoother and denser than another portion that was notcoined or electrochemical machined.

EXAMPLE 8

The method of any one or more of Examples 6 through 7, wherein theportion coined or electrochemically machined is a central portion of atleast one staple forming pocket of the annular array of staple formingpockets.

EXAMPLE 9

The method of any one or more of Examples 1 through 8, wherein the shankincludes a flange extending radially outward from a distal end of theshank.

EXAMPLE 10

The method of Example 9, wherein forming the head further comprisesforming the head to include a distal outer surface and a distal recessedportion that is disposed proximal to the distal outer surface, whereinthe distal recessed portion is sized and configured to receive theflange of the shank.

EXAMPLE 11

The method of Example 10, wherein the flange includes opposing proximaland distal surfaces, wherein coupling the head with the shank furthercomprises contacting the proximal surface of the flange with the distalrecessed portion of the head.

EXAMPLE 12

The method of Example 11, wherein contacting the proximal surface of theflange with the distal recessed portion of the head further comprisescontacting the proximal surface of the flange with the distal recessedportion of the head such that the distal outer surface of the head isgenerally flush with the distal surface of the flange.

EXAMPLE 13

The method of any one or more of Examples 9 through 12, wherein theflange includes an inner shallow portion and a rounded outer edgeportion, wherein coupling the head with the shank further comprisescoupling a proximal surface of the flange with a distal surface of thehead.

EXAMPLE 14

The method of any one or more of Examples 9 through 13, wherein couplingthe head with the shank further comprises coupling a cap with the headto sandwich the flange of the shank between the cap and the head.

EXAMPLE 15

The method of Example 14, wherein the cap includes at least oneproximally facing projection and the head includes at least onecorresponding recess, wherein coupling the cap with the head furthercomprises inserting the at least one proximally facing projection intothe at least one recess.

EXAMPLE 16

A method of manufacturing an anvil of a surgical circular stapler,wherein the anvil includes a head and a shank extending proximally fromthe head, wherein the head includes an annular array of staple formingpockets, the method comprising: (a) forming the head including theannular array of staple forming pockets; (b) coining or electrochemicalmachining at least a portion of at least one staple forming pocket ofthe annular array of staple forming pockets; (c) machining the shank;and (d) coupling the head with the shank that were separatelymanufactured.

EXAMPLE 17

The method of Example 16, wherein the portion coined orelectrochemically machined is a central portion of the at least onestaple forming pocket, wherein the central portion, once coined orelectrochemically machined, is both smoother and denser than anotherportion that was not coined or electrochemical machined.

EXAMPLE 18

The method of any one or more of Examples 16 through 17, furthercomprising: forming the shank using a metal injection molding processprior to machining the shank.

EXAMPLE 19

A surgical instrument comprising: (a) a body; (b) a shaft extendingdistally from the body; (c) a stapling head assembly positioned at adistal end of the shaft, wherein the stapling head assembly includes:(i) an anvil coupling feature, (ii) at least one annular array ofstaples, and (iii) a staple driver, wherein the staple driver isoperable to drive the at least one annular array of staples; and (d) ananvil, wherein the anvil is configured to couple with the anvil couplingfeature, wherein the anvil is further configured to deform the staplesdriven by the staple driver, wherein the anvil comprises: (i) a shank,and (ii) a head configured to be coupled with the shank, wherein thehead includes an annular array of staple forming pockets, wherein aportion of at least one staple forming pocket of the annular array ofstaple forming pockets has a smoother and denser surface than theremainder of the staple forming pocket.

EXAMPLE 20

The surgical instrument of Example 19, wherein the portion is a centralportion that is interposed between first and second outer portions,wherein the first and second outer portions have a rougher and lessdense surface than the central portion of the staple forming pocket.

EXAMPLE 21

A surgical instrument comprising: (a) a body; (b) a shaft extendingdistally from the body; (c) a stapling head assembly positioned at adistal end of the shaft, wherein the stapling head assembly includes:(i) an anvil coupling feature, (ii) at least one annular array ofstaples, and (iii) a staple driver, wherein the staple driver isoperable to drive the at least one annular array of staples; and (d) ananvil, wherein the anvil is configured to couple with the anvil couplingfeature, wherein the anvil is further configured to deform the staplesdriven by the staple driver, wherein the anvil comprises: (i) a shank,and (ii) a head configured to be coupled with the shank and formed usinga metal injection molding process, wherein the head includes an annulararray of staple forming pockets.

EXAMPLE 22

The surgical instrument of Example 21, wherein the head is machinedafter being formed using the metal injection molding process.

EXAMPLE 23

The surgical instrument of any one or more of Examples 21 through 22,wherein the head and the annular array of staple forming pocket areformed simultaneously during the metal injection molding process.

EXAMPLE 24

The surgical instrument of any one or more of Examples 21 through 23,wherein a portion of the staple forming pocket is coined orelectrochemical machined to produce the smoother and denser surface thanthe remainder of the staple forming pocket.

EXAMPLE 25

The surgical instrument of Example 24, wherein the portion coined orelectrochemically machined a central portion of at least one stapleforming pocket of the annular array of staple forming pockets.

EXAMPLE 26

The surgical instrument of any one or more of Examples 21 through 25,wherein the shank is formed using a metal injection molding process,wherein the shank includes a flange extending radially outward from adistal end of the shank.

EXAMPLE 27

The surgical instrument of Example 26, wherein the head furthercomprises a distal outer surface and a distal recessed portion that isdisposed proximal to the distal outer surface, wherein the distalrecessed portion is sized and configured to receive the flange of theshank.

EXAMPLE 28

The surgical instrument of Example 27, wherein the flange includesopposing proximal and distal surfaces, wherein the proximal surface ofthe flange is configured to contact the distal recessed portion of thehead.

EXAMPLE 29

The surgical instrument of Example 28, wherein the proximal surface ofthe flange is configured to contact the distal recessed portion of thehead such that the distal outer surface of the head is generally flushwith the distal surface of the flange.

EXAMPLE 30

The surgical instrument of any one or more of Examples 26 through 28,wherein the flange includes an inner shallow portion and a rounded outeredge portion, wherein a proximal surface of the flange is coupled with adistal surface of the head.

EXAMPLE 31

The surgical instrument of any one or more of Examples 26 through 29,wherein a cap is fixably coupled with the head to sandwich the flange ofthe shank between the cap and the head.

EXAMPLE 32

The surgical instrument of Example 31, wherein the cap includes at leastone proximally facing projection, wherein the head includes at least onecorresponding recess, wherein the at least one proximally facingprojection is configured to be inserted into the at least one recess.

IV. Miscellaneous

It should also be understood that any one or more of the teachings,expressions, embodiments, examples, etc. described herein may becombined with any one or more of the other teachings, expressions,embodiments, examples, etc. that are described herein. Theabove-described teachings, expressions, embodiments, examples, etc.should therefore not be viewed in isolation relative to each other.Various suitable ways in which the teachings herein may be combined willbe readily apparent to those of ordinary skill in the art in view of theteachings herein. Such modifications and variations are intended to beincluded within the scope of the claims.

At least some of the teachings herein may also be readily combined withone or more teachings of U.S. Pub. No. 2017/0258471, entitled “Methodsand Systems for Performing Circular Stapling,” published Sep. 14, 2017,the disclosure of which is incorporated by reference herein. Othersuitable kinds of instruments in which the teachings herein may beapplied, and various ways in which the teachings herein may be appliedto such instruments, will be apparent to those of ordinary skill in theart.

It should be appreciated that any patent, publication, or otherdisclosure material, in whole or in part, that is said to beincorporated by reference herein is incorporated herein only to theextent that the incorporated material does not conflict with existingdefinitions, statements, or other disclosure material set forth in thisdisclosure. As such, and to the extent necessary, the disclosure asexplicitly set forth herein supersedes any conflicting materialincorporated herein by reference. Any material, or portion thereof, thatis said to be incorporated by reference herein, but which conflicts withexisting definitions, statements, or other disclosure material set forthherein will only be incorporated to the extent that no conflict arisesbetween that incorporated material and the existing disclosure material.

Versions of the devices described above may have application inconventional medical treatments and procedures conducted by a medicalprofessional, as well as application in robotic-assisted medicaltreatments and procedures. By way of example only, various teachingsherein may be readily incorporated into a robotic surgical system suchas the DAVINCI™ system by Intuitive Surgical, Inc., of Sunnyvale, Calif.

Versions described above may be designed to be disposed of after asingle use, or they can be designed to be used multiple times. Versionsmay, in either or both cases, be reconditioned for reuse after at leastone use. Reconditioning may include any combination of the steps ofdisassembly of the device, followed by cleaning or replacement ofparticular pieces, and subsequent reassembly. In particular, someversions of the device may be disassembled, and any number of theparticular pieces or parts of the device may be selectively replaced orremoved in any combination. Upon cleaning and/or replacement ofparticular parts, some versions of the device may be reassembled forsubsequent use either at a reconditioning facility, or by a userimmediately prior to a procedure. Those skilled in the art willappreciate that reconditioning of a device may utilize a variety oftechniques for disassembly, cleaning/replacement, and reassembly. Use ofsuch techniques, and the resulting reconditioned device, are all withinthe scope of the present application.

By way of example only, versions described herein may be sterilizedbefore and/or after a procedure. In one sterilization technique, thedevice is placed in a closed and sealed container, such as a plastic orTYVEK bag. The container and device may then be placed in a field ofradiation that can penetrate the container, such as gamma radiation,x-rays, or high-energy electrons. The radiation may kill bacteria on thedevice and in the container. The sterilized device may then be stored inthe sterile container for later use. A device may also be sterilizedusing any other technique known in the art, including but not limited tobeta or gamma radiation, ethylene oxide, or steam.

Having shown and described various embodiments of the present invention,further adaptations of the methods and systems described herein may beaccomplished by appropriate modifications by one of ordinary skill inthe art without departing from the scope of the present invention.Several of such potential modifications have been mentioned, and otherswill be apparent to those skilled in the art. For instance, theexamples, embodiments, geometrics, materials, dimensions, ratios, steps,and the like discussed above are illustrative and are not required.Accordingly, the scope of the present invention should be considered interms of the following claims and is understood not to be limited to thedetails of structure and operation shown and described in thespecification and drawings.

1.-20. (canceled)
 21. A surgical instrument comprising: (a) a shaftextending distally; (b) a stapling head assembly positioned at a distalend of the shaft, wherein the stapling head assembly includes: (i) ananvil coupling feature, (ii) at least one annular array of staples, and(iii) a staple driver; and (c) an anvil configured to couple with theanvil coupling feature, wherein the anvil is further configured todeform the staples driven by the staple driver, wherein the anvilcomprises: (i) a shank, (ii) a head that includes an annular array ofstaple forming pockets, and (iii) a coupling member coupling the shankand the head of the anvil together.
 22. The surgical instrument of claim21, wherein the coupling member is configured to sandwich a portion ofthe shank between the coupling member and the head.
 23. The surgicalinstrument of claim 21, wherein the coupling member is overmolded ontothe shank and the head of the anvil.
 24. The surgical instrument ofclaim 21, wherein the coupling member includes a cap, wherein the capincludes at least one proximally facing projection, wherein the headincludes at least one recess, wherein the at least one proximally facingprojection is configured to be inserted into the at least one recess.25. The surgical instrument of claim 21, wherein only a predeterminedportion of at least one staple forming pocket of the annular array ofstaple forming pockets has a smoother and denser surface than theremainder of the staple forming pocket that is less dense than thepredetermined portion.
 26. The surgical instrument of claim 21, whereinthe shank includes a flange extending radially outward from a distal endof the shank, wherein the coupling member includes a cap, wherein thecap is configured to sandwich the flange of the shank between the capand the head.
 27. The surgical instrument of claim 26, wherein the capis fixably coupled with at least one of the flange of the shank or thehead.
 28. The surgical instrument of claim 26, wherein the headcomprises a distal outer surface and a distal recessed portion that isdisposed proximal to the distal outer surface, wherein the distalrecessed portion is sized and configured to receive the flange of theshank.
 29. The surgical instrument of claim 28, wherein the flangeincludes opposing proximal and distal surfaces, wherein the proximalsurface of the flange is configured to contact the distal recessedportion of the head.
 30. The surgical instrument of claim 29, whereinthe cap is coupled with the distal surface of the flange and the distalouter surface of the head.
 31. The surgical instrument of claim 29,wherein the proximal surface of the flange is configured to contact thedistal recessed portion of the head such that the distal outer surfaceof the head is generally flush with the distal surface of the flange.32. The surgical instrument of claim 26, wherein the flange includes aninner shallow portion and a rounded outer edge portion, wherein aproximal surface of the flange is coupled with a distal surface of thehead.
 33. The surgical instrument of claim 21, wherein the head isformed from a metallic material, wherein the shank is formed from ametallic material, and wherein the coupling member is formed from apolymeric material.
 34. A surgical instrument comprising: (a) a shaftextending distally; (b) a stapling head assembly positioned at a distalend of the shaft, wherein the stapling head assembly includes: (i) ananvil coupling feature, (ii) at least one annular array of staples, and(iii) a staple driver, wherein the staple driver is operable to drivethe at least one annular array of staples; and (c) an anvil configuredto couple with the anvil coupling feature, wherein the anvil is furtherconfigured to deform the staples driven by the staple driver, whereinthe anvil comprises: (i) a shank that includes a flange, (ii) a headthat includes an annular array of staple forming pockets, and (iii) acap sandwiching the flange of the shank between the cap and the head ofthe anvil.
 35. The surgical instrument of claim 34, wherein the cap isovermolded onto the flange of the shank and the head of the anvil tosandwich the flange of the shank between the cap and the head of theanvil.
 36. The surgical instrument of claim 34, wherein the head isformed from a metallic material, and wherein the shank is formed from ametallic material, wherein the cap is formed from a polymeric material.37. A method of manufacturing an anvil of a surgical circular stapler,wherein the anvil includes a head and a shank extending proximally fromthe head, the method comprising: (a) manufacturing the head and theshank separately from one another; and (b) coupling together the headand the shank of the anvil of the surgical circular stapler using atleast one overmolding process.
 38. The method of claim 37, wherein theshank includes a flange, wherein the overmolding process furthercomprises overmolding a cap onto at least one the head or the shank tosandwich a flange of the shank between the cap and the head.
 39. Themethod of claim 37, wherein coupling together the head and the shank ofthe anvil further comprises overmolding the head directly to the shankof the anvil.
 40. The method of claim 37, wherein manufacturing the headand the shank separately from one another further comprises: (a) formingthe head using a metal injection molding process; (b) forming an annulararray of staple forming pockets in the head; and (c) machining the shankof the surgical circular stapler.